1. Three masses are connected by light strings as shown in the figure
 Three masses are connected by light strings as shown in the figure. M1 = 4 kg, M2 = 2 kg, and M3 = 3 kg, The pulley is light and frictionless. Find the tension in the string connecting M2 and M3.
A. 2.3 N B. 5.7 N C N D. 0.2 N E N
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2. A 90 kg man stands on a scale in an elevator
A 90 kg man stands on a scale in an elevator. What is the acceleration (magnitude and direction) of the elevator when the scale reads 110 kg?
A. 9.8 m/s**2 upward
B. 1.8 m/s**2 downward
C. 4.3 m/s**2 upward
D. 2.2 m/s**2 upward
E. 8.0 m/s**2 downward
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3. What do we want to do today?! Sunday: 20-1-1440
A bit of housekeeping
Introduce chapter-6
Prof. Zain Yamani
Office: / 3102; Phone: ; Mobile:
HP:

4. This coming Tuesday, at 6.00 p.m. Building-6, Room-125
A bit of housekeeping
Help session
This coming Tuesday, at 6.00 p.m.
Building-6, Room-125
Problems from chapters 1-5, in sha’a Allah.
(also) Conceptual questions, for review.
Please try to (all) come..
I welcome students from other sections  but I do not intend publicize [you can invite if you want]

5. A bit of housekeeping
Attendance
If you come late, please make me aware during the (end of) the same lecture.

6. A bit of housekeeping
Laws or not a law?
Two types of truths! 

7. A bit of housekeeping
What is the acceleration of an object sliding down a smooth incline? What is the normal force?

8. Chapter-5: Newton’s Laws of Motion
Some particular forces
Applying Newton's laws

9. What are the fundamental types of forces in the Universe?
Which is the one that is predominant in nature and in technology?

10. What does “inertial reference frame” mean?
Is earth (i.e. the ground) an inertial frame or rather an non-inertial frame of reference?

11. Same forces, different masses
Same masses, different forces
Different forces, different masses

12. Can a single force be balanced?
When the net or resultant force is zero, we say the forces are balanced.
Can a single force be balanced?
How about two forces?
How about three or more forces?

13. The “free body diagram”

14. Consider an Atwood Machine where a stretch-less mass-less rope connects to masses (m2 > m1) and hangs over a mass-less frictionless pulley.
Draw a schematic diagram of the system.
Draw the free body diagram for m1.
Derive the acceleration of m1.
Taut, massless, unstretchable (or stretch-less) string

15. Some particular forces
Gravitational force
What do we mean by normal force?
What do we mean by tension?
What about the force of friction?
(static/ kinetic)

16. Applying Newton's laws

17. This (plus Newton’s 3rd Law) is how far we reached yesterday.
That is, we are done with chapter-5!!
Let’s take two more examples.

18. Applying Newton's laws

19. In the Figure, block A with 4. 0 kg mass and block B with 6
In the Figure, block A with 4.0 kg mass and block B with 6.0 kg mass, lying on a frictionless horizontal surface, are connected by a string of negligible mass. When a single force of magnitude FB = 29 N acts on block B, then both blocks move with a constant acceleration. What is the tension in the string?
A) 12 N
B) 16 N
C) 33 N
D) 9.1 N
E) 3.9 N
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20. Newton’s 3rd Law

21. Chapter-5 slides 

22. Chapter-6: Applications of Newton’s Laws
Friction
Drag force
Uniform Circular Motion

23. Friction
Static vs Kinetic
Figure out the normal force
Example: block on an incline

24. The Figure shows an initially stationary block of 1
The Figure shows an initially stationary block of 1.00 kg mass on a rough floor. A force F, of magnitude 4.90 N and making an angle  = 20.0° with the horizontal, is then applied to the block. What is the magnitude of the acceleration of the block across the floor if the coefficient of kinetic friction k = 0.300?
A) 2.17 m/s2
B) 3.62 m/s2
C) 5.73 m/s2
D) 1.55 m/s2
E) 1.01 m/s2
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25. A 3 kg block on a 30 deg incline is connected by a light string over a frictionless massless pulley to a 4 kg mass (see figure). The coefficient of kinetic friction between the block and the plane is 0.2. Find the acceleration of the blocks.
3.78 m/s**2
5.34 m/s**2
8.43 m/s**2
7.58 m/s**2
2.77 m/s**2
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26. Uniform Circular Motion
The centripetal force
Car speeding on a flat/ horizontal track
Car speeding on an inclined track
Loop the loop
Loss of sense of direction during military air maneuvers

27. A car moves on a curved, unbanked highway as shown in the figure
A car moves on a curved, unbanked highway as shown in the figure. The radius of curvature of the highway is 100 m. What is the maximum speed of the car if it is not to skid ? (coefficient of static friction between the tires and the road = 0.50)
69.3 m/s
9.11 m/s
41.0 m/s
22.1 m/s
4.01 m/s
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28. Find the tension in the string.
A 0.5 kg stone is tied to the end of a string of length 0.25 m and is rotated in a horizontal plane at a constant rate of 1.5 rev/s. The string makes an angle beta with the vertical (see figure).
Find the tension in the string.
4.04 N
48.2 N
11.1 N
29.9 N
7.11 N
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29. Chapter-6 slides 